Turnagain Pass Avalanche Forecast RSS

Archives
ARCHIVED FORECAST - All forecasts expire after 24 hours from the posting date/time.
Issued
Sat, March 12th, 2016 - 7:00AM
Expires
Sun, March 13th, 2016 - 7:00AM
Forecaster
Wendy Wagner
The Bottom Line

There is a CONSIDERABLE avalanche hazard today above 1,000′ where upwards of a foot of new snow has fallen with strong winds. A variety of avalanche problems are out there and the one most likely to impact a person are fresh wind slabs 1-2′ thick. These slabs are likely to be triggered by a person and could release naturally with warming by the sun. Additionally, wet loose snow avalanches will be likely on steep sunlit slopes. Cornice falls are possible as well today and glide avalanches continue to release.  

**Today’s message is to go into the backcountry with a conservative mind set. Constantly assess the new snow. How it is sticking (or not sticking) to the old surfaces? Keep in mind that it is springtime and sunshine will be a trigger for avalanches. Safer areas to recreate will be in mellow terrain with slopes less than 35 degrees.

If you are headed to Summit Lake, check out today’s weekly summary HERE.

Thanks to our sponsors!
Sat, March 12th, 2016
Alpine
Above 2,500'
Considerable (3)
Avalanche risk
Treeline
1,000'-2,500'
Considerable (3)
Avalanche risk
Below Treeline
Below 1,000'
No Rating (0)
Avalanche risk
Alpine
Above 2,500'
Avalanche risk
Considerable (3)
Treeline
1,000'-2,500'
Avalanche risk
Considerable (3)
Below Treeline
Below 1,000'
Avalanche risk
No Rating (0)
Danger Scale:
No Rating (0)
Low (1)
Moderate (2)
Considerable (3)
High (4)
Extreme (5)
Avalanche Problem 1
  • Storm Slabs
    Storm Slabs
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
More info at Avalanche.org

A quick hitting storm rolled through the region yesterday bringing a much needed ‘re-fresh’ to Turnagain Pass. The Turnagain Pass SNOTEL station reported 9″ of new snow beginning yesterday around noon and ending last night around midnight. This usually equates to around a foot in the Alpine. The rain/snow line was hovering just under the parking lot elevations on the Pass, around 1,000′. We did get a report of a natural avalanche seen across the Arm from Girdwood, see that and additonal info HERE. This new snow is great news, but a new set of avalanche conditions will come with it as well. These are:

Wind Slabs:  Winds associated with the snowfall were moderate to strong from a generally Easterly direction. This is a perfect recipe for forming wind slabs above treeline that could be anywhere from 1-2+’ thick. How well these fresh slabs are bonding with the old snow surface is uncertain – and something to be wary of today. The old snow surface was quite variable, harboring sun crusts on Southerly aspects, wind crusts and loose faceting snow. All of these surfaces are not likely to promote good bonding right away and our hackles should be up. Things to watch for today:

   1-  Recent avalanches, the skies should clear for good visibility
   2-  Cracking or collapsing in the new snow
   3-  Slopes that have been windloaded – Avoid these today, give them a chance to adjust
   4-  SUN…. If the sun comes out slabs could release naturally with the warming!

Loose Snow Avalanches:  Once the sun does come out (today or tomorrow) damp/wet sluffs are likely to run naturally. These will also be easily triggered by a person. Sluffs should entrain mostly just the new snow, so how much new snow is on a slope will depend on how large the sluff is. 

Cornices:  Another round of snow and wind will only add to the weight of these truck size features overhanging many slopes. Extra caution is warranted when choosing how you travel along ridgelines – give cornices an extra wide berth. Also, limit time under these, they could fall on their own and the sun warming them will add to this possibility.

Avalanche Problem 2
  • Glide Avalanches
    Glide Avalanches
Glide Avalanches
Glide Avalanches are the release of the entire snow cover as a result of gliding over the ground. Glide avalanches can be composed of wet, moist, or almost entirely dry snow. They typically occur in very specific paths, where the slope is steep enough and the ground surface is relatively smooth. They are often proceeded by full depth cracks (glide cracks), though the time between the appearance of a crack and an avalanche can vary between seconds and months. Glide avalanches are unlikely to be triggered by a person, are nearly impossible to forecast, and thus pose a hazard that is extremely difficult to manage.
More info at Avalanche.org

AVOID travel under glide cracks. This week has been a particularly active glide avalanche cycle. Glide cracks continue to threaten large areas of terrain throughout Turnagain Pass, Girdwood, and Summit Lake. There were several new glide avalanches seen Wednesday from the Seward Hwy, and a large glide released on the East face of Seattle Ridge a few days ago. Glide cracks are on all aspects within the mid-elevation band (1000′-2500′), and some areas like the SW face of Cornbiscuit and Tincan are covered. This avalanche problem is impossible to predict and is not associated with human triggers. We have been talking about the glide avalanche problem for over two months in the advisory and as long as glide cracks continue to open up, move and release, we will stress the importance of avoiding them

Weather
Sat, March 12th, 2016

Yesterday saw a quick moving disturbance move through. Visibility was poor as rain fell below 800-1,000′ with snow above. The Turnagain Pass SNOTEL site has reported 9″ of new snow at 2,000′. Winds associated with the snowfall were 20-25mph from the East along the ridgetops with stronger gusts. Temperatures have been warm, in the mid 30’s F at 1,000′ and the mid 20’sF at 3,500′.

Overnight, snowfall has stopped and winds have died down. For today, skies should begin to clear up as the system exists the region; we are expecting the sun to come out for the afternoon. Winds today are expected to be light, 5-10mph, from a generally East direction and temperatures warm, up to 40F at 1,000′ and the upper 20’sF in the Alpine.  

Sunday and into Monday looks to be mostly clear as well with sunny skies and light Easterly ridgetop winds.

PRECIPITATION 24-hour data (6am – 6am)

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′) 31   9   0.9   143  
Summit Lake (1400′) 35   0   0   43  
Alyeska Mid (1700′) 32   5   0.7   110  

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) 24   NE   18   43  
Seattle Ridge (2400′) 26   SE   16   35  
Observations
Recent Observations for Turnagain Pass
Date Region Location
12/10/19 Turnagain Avalanche: Tincan and Sunburst from the air
12/10/19 Turnagain Observation: Tincan
12/08/19 Turnagain Avalanche: Tincan
12/06/19 Turnagain Avalanche: Sunburst
12/04/19 Turnagain Observation: Sunburst
12/03/19 Turnagain Observation: Hippy Bowl
12/01/19 Turnagain Observation: Tincan, All elevations
12/01/19 Turnagain Observation: Tincan
11/30/19 Turnagain Observation: Tincan Treeline Plateau/ Common Bowl/ Ridge
11/29/19 Turnagain Observation: Sunburst Ob #2
Riding Areas
Updated Wed, December 11th, 2019

Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: mailroom_r10_chugach@fs.fed.us

Area Status Weather & Riding Conditions
Glacier District
Johnson Pass
Closed
Closed.
Placer River
Closed
Closed.
Skookum Drainage
Closed
Closed.
Turnagain Pass
Closed
Closed.
Twentymile
Closed
Closed.
Seward District
Carter Lake
Closed
Closed.
Lost Lake Trail
Closed
Closed.
Primrose Trail
Closed
Closed.
Resurrection Pass Trail
Closed
Closed. Will be open for the 2019/20 season pending adequate snow cover.
Snug Harbor
Closed
Closed.
South Fork Snow River Corridor
Closed
Closed.
Summit Lake
Closed
Closed.

Subscribe to Turnagain Pass
Avalanche Forecast by Email